U.S. Pat. No. 4,896,149, issued Jan. 23, 1990, to Buzak et al. ("'149 Patent") and assigned to the assignee of the present application, discloses an addressing structure using an ionizable gaseous medium. Such an addressing structure may be used in a system constructed of data storage elements which addresses those data storage elements with the use of an ionizable gas. An example of such a system is a flat panel display, a video camera, or a memory system.
The system disclosed in the '149 patent has an electrode structure which defines rows of channels, each of which is filled with an ionizable gas. Extending along the base of each of those channels are a row electrode and a reference electrode. The row electrode is electrically driven as a cathode, and the reference electrode is referenced to ground and acts as an anode when the row electrode is electrically driven as a cathode. When a particular row electrode is driven as a cathode, the ionizable gas in the particular channel which contains that row electrode is ionized, and the system operates as disclosed in the '149 patent.
One embodiment of the system disclosed in the '149 patent is a flat panel display system in which the electric field across an electro-optic material containing a liquid crystal material is changed in response to data signals provided over data electrodes.
Several types of distortion are observed when operating such a flat panel display. Low or high intensity (e.g., generally black or generally white) streaks (in this case, gradients in intensity) often appear in a direction transverse to the length of a channel between the two sides of individual display elements ("pixels") defined in part by the channel ("cross-talk across the width of a pixel"). In addition, low, intermediate, and high intensity (e.g., generally black, grey, and generally white) streaks extending along the length of a channel (i.e., parallel to the reference electrode and the row electrode) often appear between the two sides of pixels above a channel that contains multiple pixels that are intended to have highest intensity (e.g., to appear black) ("horizontal cross-talk along the length of a channel"). In addition, pixels often flicker between low, intermediate, and high intensity ("flicker") or continue to display an image from a preceding image field ("image sticking"). All these types of distortion interfere with proper imaging of high and low intensity pixels and proper production of grey scale levels and color intensity levels in pixels.
Other types of cross-talk interference which may arise in the operation of a flat panel liquid crystal display in accordance with the '149 patent are addressed in U.S. patent applications Ser. Nos. 07/854,145, for REDUCING CROSS TALK EFFECTS IN ELECTRO-OPTICAL ADDRESSING STRUCTURES, filed Mar. 19, 1992; 07/958,631 for an ADAPTIVE DRIVE WAVEFORM FOR REDUCING CROSSTALK EFFECTS IN ELECTRO-OPTICAL ADDRESSING STRUCTURES, filed Oct. 9, 1992; and 08/026,367 for an ELECTRO-OPTICAL ADDRESSING STRUCTURE HAVING REDUCED SENSITIVITY TO CROSS-TALK, filed concurrently herewith. A type of image distortion that may occur in the operation of such a flat panel display is discussed in U.S. patent application Ser. No. 08/026,366, for a KICKER PULSE CIRCUIT FOR AN ADDRESSING STRUCTURE USING AN IONIZABLE GASEOUS MEDIUM, filed concurrently herewith. Each of those applications is assigned to the assignee of the present application. It is preferable to eliminate cross-talk and other distortion to the greatest practicable extent in the operation of a flat panel liquid crystal display in accordance with the '149 patent.
There is accordingly a need to reduce or eliminate any one or more of the specific distortions of cross-talk across the width of a pixel, horizontal cross-talk along the length of a channel, flicker, and image sticking in the operation of such flat panel displays.